The present invention relates to grinding machines and more specifically to flat surface grinding machines and to grinding machines for machining workpieces such as broaches.
Grinding machines that have a tangential wheelhead and grind flat surfaces are well known.
Specific sharpening machines for manufacturing broaches of any type are also well known.
U.S. Pat. No. 3,851,563 discloses a machine for machining workpieces such as broaches. The machine has a single wheelhead and enables the wheelhead to be orientated in such a way that the helical grinding of the workpiece can be executed at a given angle.
U.S. Pat. No. 4,461,121 describes a grinding machine with at least three wheels offering the possibility of the relative positioning of the workpiece to be ground and the wheels so as to execute said workpiece in accordance with the specifications that this is to have.
The object of the invention is to provide a flat surface grinding machine that has a second wheelhead for machining workpieces such as broaches, as defined in the claims.
With the machine that is the object of the invention, a conventional flat surface grinding machine may also be used for machining broaches by including for this purpose a second retracting wheelhead rotatable about its own axis.
The advantages that stem from the invention are as follows:
There is no need to build a machine specifically for machining broaches, as the flat surface grinding machine may be used.
A sturdy machine is obtained.
The working of the machine is simple. The transition from machining with the first wheelhead to machining with the second wheelhead and vice versa is done by numeric control by means of the vertical movement of the first wheelhead and the horizontal movement of the second wheelhead in relation to the first wheelhead, no other type of operation, such as the manual replacement of one wheelhead for another, being necessary.
When the second wheelhead is in the rest position the arrangement is such that it does not restrict the travel of the machine.